Prevalence of class 1 integrons and plasmid-mediated qnr-genes among Enterobacter isolates obtained from hospitalized patients in Ahvaz, Iran.

Quinolones are frequently used classes of antimicrobials in hospitals, crucial for the treatment of infections caused by Gram-negative bacteria. The inappropriate use of quinolones and other antimicrobial agents for the treatment of bacterial infections leads to a significant increase of resistant isolates. The acquisition of antimicrobial resistance may be related to achievement of resistance determinant genes mediated by plasmids, transposons and gene cassettes in integrons. The objective of this cross-sectional study, conducted from December 2015 to July 2016 at two teaching hospitals in Ahvaz, southern Iran, was to screen for the presence of class 1 integrons and quinolone resistance genes in clinical isolates of Enterobacter spp. In all, 152 non-duplicated Enterobacter isolates were collected from clinical specimens and identified as Enterobacter spp. using standard microbiological methods. Antimicrobial susceptibility test was determined using the disc diffusion method according to the CLSI recommendation. Determination of class 1 integrons and PMQR genes was assessed by PCR. Analysis of antibiotic susceptibility tests showed that the highest antibiotic resistance was toward ciprofloxacin (55.3%), while the lowest level was observed against meropenem (34.9%). Moreover, 47.4% (72/152) and 29% (44/152) of isolates were positive for class 1 integron and quinolone resistance genes, respectively. The relative frequencies of antibiotic resistance were significantly higher among class 1 integron-positive isolates. In summary, our results highlight the importance of PMQR genes in the emergence of quinolone-resistant Enterobacter isolates. Moreover, it seems that class 1 integrons have a widespread distribution among Enterobacter isolates and have clinical relevance to multiple-drug-resistant isolates.

[1]  A. Peymani,et al.  Plasmid-Mediated Quinolone-Resistance (qnr) Genes in Clinical Isolates of Escherichia coli Collected from Several Hospitals of Qazvin and Zanjan Provinces, Iran , 2016, Osong public health and research perspectives.

[2]  A. Peymani,et al.  High prevalence of plasmid-mediated quinolone resistance determinants in Enterobacter cloacae isolated from hospitals of the Qazvin, Alborz, and Tehran provinces, Iran. , 2016, Revista da Sociedade Brasileira de Medicina Tropical.

[3]  Lei Chen,et al.  Resistance integrons: class 1, 2 and 3 integrons , 2015, Annals of Clinical Microbiology and Antimicrobials.

[4]  Z. Salehi,et al.  Prevalence of Class 1 Integrons and Extended Spectrum Beta Lactamases among Multi-Drug Resistant Escherichia coli Isolates from North of Iran , 2015, Iranian biomedical journal.

[5]  B. Soltani,et al.  Multidrug-Resistant Escherichia coli and Klebsiella pneumoniae Isolated From Patients in Kashan, Iran , 2015, Jundishapur journal of microbiology.

[6]  M. Ahangarzadeh Rezaee,et al.  Carriage of Class 1 and 2 Integrons in Quinolone, Extended-Spectrum-β-Lactamase-Producing and Multi Drug Resistant E.coli and K.pneumoniae: High Burden of Antibiotic Resistance. , 2015, Advanced pharmaceutical bulletin.

[7]  M. Goudarzi,et al.  Prevalence of Plasmid-Mediated Quinolone Resistance Determinants and OqxAB Efflux Pumps among Extended-Spectrum β-Lactamase Producing Klebsiella pneumoniae Isolated from Patients with Nosocomial Urinary Tract Infection in Tehran, Iran , 2015, Scientifica.

[8]  A. Peymani,et al.  Emergence of plasmid-mediated quinolone-resistant determinants in Klebsiella pneumoniae isolates from Tehran and Qazvin provinces, Iran , 2015, Journal of preventive medicine and hygiene.

[9]  J. Pagés,et al.  Enterobacter aerogenes and Enterobacter cloacae; versatile bacterial pathogens confronting antibiotic treatment , 2015, Front. Microbiol..

[10]  T. Peto,et al.  Dynamics of MDR Enterobacter cloacae outbreaks in a neonatal unit in Nepal: insights using wider sampling frames and next-generation sequencing , 2015, The Journal of antimicrobial chemotherapy.

[11]  A. Peymani,et al.  Emergence of TEM, SHV, and CTX-M-extended spectrum β-lactamases and class 1 integron among Enterobacter cloacae isolates collected from hospitals of Tehran and Qazvin, Iran. , 2014, Microbial drug resistance.

[12]  Tülin Demir,et al.  Pneumonia due to Enterobacter cancerogenus infection , 2014, Folia Microbiologica.

[13]  Michael R Gillings,et al.  Integrons: Past, Present, and Future , 2014, Microbiology and Molecular Reviews.

[14]  G. Jacoby,et al.  Plasmid-Mediated Quinolone Resistance , 2008, Microbiology spectrum.

[15]  C. Landersdorfer,et al.  Combination therapy for carbapenem-resistant Gram-negative bacteria , 2013, Expert review of anti-infective therapy.

[16]  S. Siadati,et al.  Drug Resistance of Pseudomonas aeruginosa and Enterobacter cloacae Isolated from ICU, Babol, Northern Iran , 2013, International journal of molecular and cellular medicine.

[17]  I. Nikokar,et al.  Antibiotic resistance and frequency of class 1 integrons among Pseudomonas aeruginosa, isolated from burn patients in Guilan, Iran , 2013, Iranian journal of microbiology.

[18]  R. Mirnejad,et al.  Antibiotic resistance and carriage class 1 and 2 integrons in clinical isolates of Acinetobacter baumannii from Tehran, Iran. , 2013, Asian Pacific journal of tropical biomedicine.

[19]  Zeina A Kanafani,et al.  Current concepts in antimicrobial therapy against resistant gram-negative organisms: extended-spectrum beta-lactamase-producing Enterobacteriaceae, carbapenem-resistant Enterobacteriaceae, and multidrug-resistant Pseudomonas aeruginosa. , 2011, Mayo Clinic proceedings.

[20]  Surbhi Leekha,et al.  General Principles of Antimicrobial Therapy , 2011, Mayo Clinic proceedings.

[21]  P. Brown,et al.  The emergence of qnr-mediated quinolone resistance among Enterobacteriaceae in Jamaica. , 2009, The West Indian medical journal.

[22]  E. Roma,et al.  Prevalence and characterization of class 1 integrons in Escherichia coli of poultry and human origin. , 2009, Foodborne pathogens and disease.

[23]  L. Martínez-Martínez,et al.  Detection of Plasmid-Mediated Quinolone Resistance Genes in Clinical Isolates of Enterobacter spp. in Spain , 2009, Journal of Clinical Microbiology.

[24]  E. Giralt,et al.  Mechanism of action of and resistance to quinolones , 2008, Microbial biotechnology.

[25]  P M Bennett,et al.  Plasmid encoded antibiotic resistance: acquisition and transfer of antibiotic resistance genes in bacteria , 2008, British journal of pharmacology.

[26]  A. Robicsek,et al.  qnr Prevalence in Ceftazidime-Resistant Enterobacteriaceae Isolates from the United States , 2006, Antimicrobial Agents and Chemotherapy.

[27]  G. Taylor,et al.  Five years of nosocomial Gram-negative bacteremia in a general intensive care unit: epidemiology, antimicrobial susceptibility patterns, and outcomes. , 2006, International journal of infectious diseases : IJID : official publication of the International Society for Infectious Diseases.

[28]  David W. Russell,et al.  Purification of nucleic acids by extraction with phenol:chloroform. , 2006, CSH protocols.

[29]  M. Domínguez,et al.  Prevalence and types of class 1 integrons in aminoglycoside-resistant Enterobacteriaceae from several Chilean hospitals. , 2003, The Journal of antimicrobial chemotherapy.

[30]  E. Goldstein,et al.  Widespread use of fluoroquinolones versus emerging resistance in pneumococci. , 2002, Clinical infectious diseases : an official publication of the Infectious Diseases Society of America.

[31]  W. L. Yu,et al.  Outbreak investigation of nosocomial enterobacter cloacae bacteraemia in a neonatal intensive care unit. , 2000, Scandinavian journal of infectious diseases.

[32]  R. Hall.  Mobile gene cassettes and integrons: moving antibiotic resistance genes in gram-negative bacteria. , 2007, Ciba Foundation symposium.